Loading...

Theoretical Assessment of the Corrosion Inhibitory Effect of Some Derivatized Benzaldehyde Based Schiff Bases

Sakhaei Nia, Abed | 2014

639 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 46117 (03)
  4. University: Sharif University of Technology
  5. Department: Chemistry
  6. Advisor(s): Gobal, Freydoon
  7. Abstract:
  8. Schiff bases are used as prevalent ligands in coordination chemistry and are prepared easily. Their application as mild inhibitory agents for prevention of various steel’s corrosion in acidic solution has been proved. When their structure is altered, multi-purpose application for them is found. This property has led to a motive for research and study. In this study, electronic properties of a group of Schiff bases are investigated. The goal of this study is using quantum mechanics (QM) as a tool for specifying electronic properties of some of these bases. With respect to QM calculation which is done by density functional theory (DFT), their properties as inhibitory agents are studied. First, some of theoretical indices like hardness, energy level of HOMO and LUMO orbitals, thefraction of electrons transferred and so on are assessed. Then on the basis of the best theoretical index, the calculated data for this group of bases is assessed. And finally, the effect of different factors such as different functional groups, the number of active inhibitory sites, conjugation etc., on the inhibitory strength are studied. Schiff bases for which the experimental data are in hand, were comparedwith theoretical indices and it was revealed that the best index which predicted the proper trend of experimental data, was hardness. Then, by considering the hardness as a proper factor, it revealed that the higher the aromaticity in the structure of inhibitor leads to a higher level of inhibitory character. Also it revealed that the presence of electron donor functional groups like thiol and hydroxide, have a huge contribution to inhibitory strength. Moreover it found that Schiff bases demonstrate higher inhibitory character in acidic media. Finally we come to the conclusion that the presence of phosphorous atom, instead of nitrogen atom, in the structure of the base increases the inhibitory character significantly and that the conjugation of active sites of the base has a big effect on the strength of the inhibitory character
  9. Keywords:
  10. Density Functional Theory (DFT) ; Inhibitor ; Schiff Bases

 Digital Object List

 Bookmark

No TOC